1. Field of the Invention
The present invention relates to golf balls. Specifically, the present invention relates to improvement of dimples of golf balls.
2. Description of the Related Art
Golf balls have a large number of dimples on the surfaces thereof. The dimples disturb the airflow around the golf ball during flight to cause turbulent flow separation. This phenomenon is referred to as “turbulization”. Due to the turbulization, separation points of the air from the golf ball shift backwards leading to a reduction of drag. The turbulization promotes the displacement between the separation point on the upper side and the separation point on the lower side of the golf ball, which results from the backspin, thereby enhancing the lift force that acts upon the golf ball. Excellent dimples efficiently disturb the air flow. The excellent dimples produce a long flight distance.
In designing a dimple pattern, the surface of a golf ball is divided into a plurality of units. Dimples are located in each unit. For the purpose of obtaining the units, a regular polyhedron or quasi-regular polyhedron inscribed in a phantom sphere of the golf ball may be used. By projecting the sides of these polyhedrons on the phantom sphere, comparting lines are obtained. By the comparting lines, the units are obtained. Examples of the regular polyhedron include a regular hexahedron, a regular octahedron, a regular dodecahedron, and a regular icosahedron. Examples, of the quasi-regular polyhedron include a cuboctahedron and an icosidodecahedron.
In a dimple pattern based on a cuboctahedron, the surface of a golf ball is divided into spherical quadrangles and spherical triangles. The dimple pattern based on the cuboctahedron is varied. In a golf ball having this pattern, turbulization can be prompted. Documents disclosing a dimple pattern based on a cuboctahedron are, for example, JPS63-186670, JPH1-221182, JPH2-211181, and JP2002-331044.
The greatest interest of golf players concerning golf balls is flight distance. In light of flight performance, there is room for further improvement in the dimple pattern based on the cuboctahedron. An object of the present invention is to provide a golf ball having excellent flight performance.